How is the concept of subrogation compatible with the principles of indemnity? Justify your answer with an example.

An insured open an accident insurance contract with three insurance companies. The details are as follows:

Policy A Sum insured TK 20000

Policy B Sum insured Tk 30000

Policy C Sum Insured Tk 50000

If the total amount of loss arises from an accident insurance is Tk 1000, then how the contribution principle will work here to distribute the loss among the insurer.